Field of the Invention
This invention relates generally to apparatus for determining deformation in vehicle bodies and the like. More specifically, in its most preferred embodiment, this invention relates to apparatus for comparing the actual three dimensional spatial coordinates of manufacturer-provided reference points in a vehicle with their normal or specification values to thereby determine if the vehicle is deformed. In a general sense, this invention also concerns apparatus for determining two and three dimensional spatial co-ordinates of objects from each other and from a base which is physically distant from and unconnected with the objects, through the use of beams such as laser light beams.
In the past, vehicles such as automobiles had structural frames on which vehicles including body panels were built. Repair of accidental vehicle damage involved straightening the frame, and re-shaping or replacing body panels. Vehicle technology then accelerated to meet needs such as low fuel consumption, and most passenger vehicles came to have unibody construction. In a unibody vehicle, no distinct frame exists apart from the body panels; instead, like an egg carton, the panels together form a "unibody". Substantial weight is saved.
With either form of vehicle, frame or unibody, repair is greatly speeded, and repair quality greatly improved, with a frame (and unibody) straightening machine such as described in U.S. Pat. No. Re. 31,636 issued to F. Lavell Chisum (incorporated by reference). The Chisum machine has attributes which have withstood the test of time, and the machine has been continuously manufactured and sold since its invention by Chief Automotive Systems, Inc. (or its predecessors) of Grand Island, Nebr. as the Chief EZ Liner.TM..
The Chief EZ Liner.TM. machine speeds frame and unibody straightening, but was not intended to, and does not by itself, provide information as to the extent of straightening to be accomplished. Vehicles currently have manufacturer-provided unibody reference points, such as reference openings or holes, and specifications are published for the correct three-dimensional locations of the reference points relative to each other. If a vehicle is involved in an accident, these reference points will be moved from their "normal", "specification", or pre-accident positions with respect to each other. Most, if not all, vehicle frame and unibody straightening jobs require return of the vehicle reference points to within specification.
In association with the Chief EZ Liner.TM. machine, operators may use only their training and experience to measure the extent of straightening to be accomplished, but most often employ gauges such as the advanced gauges described in U.S. Pat. Nos. 4,689,888 and 4,731,936, issued Sep. 1, 1987 and Mar. 22, 1988, respectively (incorporated by reference). By referring to the data provided by manufacturers in KLM Body and Chassis Dimension and Specification Charts (Specification Manuals), and by employing gauges, operators can determine which portions of vehicles to straighten, and how deformed the vehicles are.